/*
 * yauosk - Yet Another Useless Operating System Kernel
 *
 * Copyright (c) 2009-2010 Matteo Cicuttin
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 * derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch/x86/machine.h>

#include <sys/types.h>
#include <systm.h>


#define	VGA_IO_BASE		0x3d4
#define	VGA_MEM_BASE	0xB8000

void
biostty_putc(int c)
{
	int cur;
	ushort *vga_mem = (ushort *) VGA_MEM_BASE;
	
	outb(VGA_IO_BASE, 14);
	cur = inb(VGA_IO_BASE + 1) << 8;
	outb(VGA_IO_BASE, 15);
	cur |= inb(VGA_IO_BASE + 1);
	
	c &= 0xff;
	
	if (c == '\n') /* Newline? Move cursor to new line */
	{
		cur -= (cur % 80);
		cur += 80;
	}
	else /* Otherwise print c */
	{
		c |= 0x0700;
		vga_mem[cur] = c;
		cur++;
	}
	
	if ( (cur/80) >= 24 )
	{
		memmove(vga_mem, vga_mem+80, sizeof(ushort) * (80*23));
		cur -= 80;
		bzero(vga_mem + cur, sizeof(ushort) * ((80*24)-cur));
	}
	
	outb(VGA_IO_BASE, 14);
	outb(VGA_IO_BASE + 1, cur >> 8);
	outb(VGA_IO_BASE, 15);
	outb(VGA_IO_BASE + 1, cur);
}

void
biostty_init(void)
{
	printf("biosconsole: initialized\n");
}


